{"id":"CVE-2021-27565","aliases":["EUVD-2021-14316","GHSA-r4v2-qg7m-3xrh"],"status":"published","title":"The web server in InterNiche NicheStack through 4.0.1 allows remote attackers to cause a denial...","description":"The web server in InterNiche NicheStack through 4.0.1 allows remote attackers to cause a denial of service (infinite loop and networking outage) via an unexpected valid HTTP request such as OPTIONS. This occurs because the HTTP request handler enters a miscoded wbs_loop() debugger hook.","severity":{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-12","score":0.02588,"percentile":0.85482,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-835"],"published":"2021-08-19T11:04:23Z","modified":"2026-06-17T03:45:08Z","products":[{"vendor":"hcc-embedded","product":"nichestack"}],"references":[{"url":"https://www.hcc-embedded.com/","tags":["x_refsource_MISC","x_transferred","Product"]},{"url":"https://www.hcc-embedded.com/about/about-interniche","tags":["x_refsource_MISC","x_transferred","Product"]},{"url":"https://www.forescout.com/blog/new-critical-operational-technology-vulnerabilities-found-on-nichestack/","tags":["x_refsource_MISC","x_transferred","Mitigation","Third Party Advisory"]},{"url":"https://www.kb.cert.org/vuls/id/608209","tags":["third-party-advisory","x_refsource_CERT-VN","x_transferred","Third Party Advisory","US Government Resource"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-27565"},{"url":"https://github.com/advisories/GHSA-r4v2-qg7m-3xrh"}],"sources":{"cve":[{"id":"CVE-2021-27565","description":"The web server in InterNiche NicheStack through 4.0.1 allows remote attackers to cause a denial of service (infinite loop and networking outage) via an unexpected valid HTTP request such as OPTIONS. This occurs because the HTTP request handler enters a miscoded wbs_loop() debugger hook.","status":"published","published":"2021-08-19T11:04:23Z","modified":"2024-08-03T21:26:09.982Z","updated_at":"2026-11-02T14:33:04.679189Z"}],"euvd":[{"id":"EUVD-2021-14316","description":"The web server in InterNiche NicheStack through 4.0.1 allows remote attackers to cause a denial of service (infinite loop and networking outage) via an unexpected valid HTTP request such as OPTIONS. This occurs because the HTTP request handler enters a miscoded wbs_loop() debugger hook.","status":"published","published":"2021-08-19T11:04:23Z","modified":"2024-08-03T21:26:09Z","updated_at":"2026-11-03T03:24:48.919164Z"}],"ghsa":[{"id":"GHSA-r4v2-qg7m-3xrh","title":"The web server in InterNiche NicheStack through 4.0.1 allows remote attackers to cause a denial...","description":"The web server in InterNiche NicheStack through 4.0.1 allows remote attackers to cause a denial of service (infinite loop and networking outage) via an unexpected valid HTTP request such as OPTIONS. This occurs because the HTTP request handler enters a miscoded wbs_loop() debugger hook.","status":"published","published":"2022-05-24T19:11:41Z","modified":"2023-01-30T05:01:35Z","cwes":["CWE-835"],"updated_at":"2026-11-02T14:46:26.483285Z"}],"nvd":[{"id":"CVE-2021-27565","description":"The web server in InterNiche NicheStack through 4.0.1 allows remote attackers to cause a denial of service (infinite loop and networking outage) via an unexpected valid HTTP request such as OPTIONS. This occurs because the HTTP request handler enters a miscoded wbs_loop() debugger hook.","status":"published","published":"2021-08-19T12:15:08.627Z","modified":"2026-06-17T03:45:08.697Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"primary"},{"version":"2.0","score":5,"vector":"AV:N/AC:L/Au:N/C:N/I:N/A:P","level":"medium","assessor":"primary"}],"cwes":["CWE-835"],"updated_at":"2026-11-02T14:06:57.318236Z"}]}}